STUMPED! Engine backfires when choking and will not start up! 85 HP L-drive

shadow7g

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Joined
May 9, 2011
Messages
23
I was given an 84 bayliner capri with a 85 HP force L-drive by my brother. The last time he took it out was 4 years ago and it shut off on him. After sitting in my yard, and the floor system rotting (thank god it was only the floor and not the stringers). Ive completely gutted the rotten wood and plan on using treated lumber and blah blah blah just so i can have a learning boat. ANYWHO! After hours of figuring stuff out i came to the conclusion cylinder #3 had no fire, so i did some tracing, wiring in different order and turns out the CDI box was bad. Ok, got a new CDI box and STILL NO FIRE to #3. After more wire splicing, turns out the trigger was bad. Got a new trigger, YAY fire on ALL 3 cylinders, beautiful, bright, blue spark! Man, im in heaven, NOT! It turns over and turns over and turns over, i choke it goes BANG! Ive checked wiring and its all wired to factory specs, i did however cross cylinders 1&2 with eachother and i got a little smoke and the sound of an engine that wanted to start for about 4 seconds, then it turns and turns and turns and turns! NOTHING! After reading and reading and reading all i can come up with is timing. Maybe i didnt put the flywheel back on the key correctly. Ive tried every spark plug wire combination you can think of. Here is all of the things ive done so far.

1. Replace CDI box
2. Replace trigger
3. Replace primer bulb
4. Rebuilt fuel pump
5. Cleaned carbs
6. Made sure the reed valves arent stuck shut
7. Sprayed fuel into the carbs
8. Tried different firing orders
9. Made sure i have spark on numerous occasions
10. Manually moving timing trigger

I know my fuel is good because i can see it dripping out if i choke it for more than a few seconds on each carb. Ive ruled it down to 1 of 2 things.

1. Gas is bad
2. Key fell off while putting the flywheel back on and the timing is off.

Any other suggestions? Im mechanically inclined but im dumb as hell when it comes to marine stuff. However, ive learned a good bit the past 2 weeks. Any help would be greatly appreciated and it would surely save another boat from going to the junk yard.

Sorry for the long post but i wanted to be very descriptive

Thanks,
johnas
 

tater76

Senior Chief Petty Officer
Joined
May 7, 2010
Messages
712
Re: STUMPED! Engine backfires when choking and will not start up! 85 HP L-drive

Did you torque the flywheel, or just tighten it down till it was tight? Could have a sheared flywheel key.
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,762
Re: STUMPED! Engine backfires when choking and will not start up! 85 HP L-drive

sheared flywheel key or wiring from trigger is wrong.
 

shadow7g

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Joined
May 9, 2011
Messages
23
Re: STUMPED! Engine backfires when choking and will not start up! 85 HP L-drive

Im going to pull the flywheel off today when i get home from work. Its highly possible that the key fell off when i installed the flywheel. The trigger wiring is "correct". I bought a used one with factory wiring harness. I have a factory service manual and a seloc. Ill try to track down firing order today. Top piston is #1 middle is #2 and last is #3 right? Which order is the trigger? I guess im going to have to turn the motor over by hand and find TDC of each cylinder and check out the spark.
 

shadow7g

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May 9, 2011
Messages
23
Re: STUMPED! Engine backfires when choking and will not start up! 85 HP L-drive

Sweet deal! It runs! Turns out that the trigger wiring wasnt for my engine. I guess it was for a different engine? Or a different year? All the cylinders were way off of timing. I went with the wiring that my engine had and it fired right up! First time in 4 years and she purrrrrrs like a kitty! I think the idle is a little high though, how can i adjust the idle?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,089
Re: STUMPED! Engine backfires when choking and will not start up! 85 HP L-drive

20023.jpgFigure out what the towershaft is and adjust it from that.
Idle in gear and warm in the water should be about 750-800 Jerry
 

shadow7g

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May 9, 2011
Messages
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Re: STUMPED! Engine backfires when choking and will not start up! 85 HP L-drive

What should the idle be in neutral?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,089
Re: STUMPED! Engine backfires when choking and will not start up! 85 HP L-drive

In neutral around 1000-1200.Then do final adjustment in the water.If you don't have it at 750-800 in gear in the water.It's gonna stall. If the idle is too high you can damage the clutch dog and gears.J
 

shadow7g

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Joined
May 9, 2011
Messages
23
Re: STUMPED! Engine backfires when choking and will not start up! 85 HP L-drive

Alright! Got my interior done and painted. Set my carbs to all open fully at WOT and set my WOT timing to 28 degrees. Now all i need is for my brother to get off his *** and register this boat so i can take this thing out for a test spin! Im excited.
 
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